Gimp is an open source project that rivals photo shop that is available for mac and pc. It is a free software graphics editor that is primarily used as an image retouching and editing tool . Gimp for mac has many features and is very useful for everyday image editing. The project has been in development since 1995 so you can be sure that it will be regularly updated. Gimp has more recently become available for mac and has proven so far to be running on macs very well.GIMP will only run on Mac OS X, not on version 9 or earlier of the Macintosh operating system. Downlod gimp for mac here.